#!/bin/sh

# A script to bootstrap cabal-install.

# It works by downloading and installing the Cabal, zlib and
# HTTP packages. It then installs cabal-install itself.
# It expects to be run inside the cabal-install directory.

# install settings, you can override these by setting environment vars
PREFIX=${PREFIX:-${HOME}/.cabal}
#VERBOSE
#EXTRA_CONFIGURE_OPTS

# programs, you can override these by setting environment vars
GHC=${GHC:-ghc}
GHC_PKG=${GHC_PKG:-ghc-pkg}
WGET=${WGET:-wget}
CURL=${CURL:-curl}
TAR=${TAR:-tar}
GUNZIP=${GUNZIP:-gunzip}
SCOPE_OF_INSTALLATION="--user"


for arg in $*
do
  case "${arg}" in
    "--user")
      SCOPE_OF_INSTALLATION=${arg}
      shift;;
    "--global")
      SCOPE_OF_INSTALLATION=${arg}
      PREFIX="/opt/sfw/libexec/cabal"
      shift;;
    *)
      echo "Unknown argument or option, quitting: ${arg}"
      echo "usage: bootstrap.sh [OPTION]"
      echo
      echo "options:"
      echo "   --user    Install for the local user (default)"
      echo "   --global  Install systemwide"
      exit;;
  esac
done


# Versions of the packages to install.
# The version regex says what existing installed versions are ok.
PARSEC_VER="2.1.0.1";  PARSEC_VER_REGEXP="2\."     # == 2.*
NETWORK_VER="2.2.1.5"; NETWORK_VER_REGEXP="2\."    # == 2.*
CABAL_VER="1.8.0.2";   CABAL_VER_REGEXP="1\.8\."   # == 1.8.*
MTL_VER="1.1.0.2";     MTL_VER_REGEXP="1\.1\."     # == 1.1.*
HTTP_VER="4000.0.8";   HTTP_VER_REGEXP="4000\.0"   # == 4000.0.*
ZLIB_VER="0.5.2.0";    ZLIB_VER_REGEXP="0\.[45]\." # == 0.5.*

HACKAGE_URL="http://hackage.haskell.org/packages/archive"

die () {
  echo
  echo "Error during cabal-install bootstrap:"
  echo $1 >&2
  exit 2
}

# Check we're in the right directory:
grep "cabal-install" ./cabal-install.cabal > /dev/null 2>&1 \
  || die "The bootstrap.sh script must be run in the cabal-install directory"

${GHC} --numeric-version > /dev/null \
  || die "${GHC} not found (or could not be run). If ghc is installed make sure it is on your PATH or set the GHC and GHC_PKG vars."
${GHC_PKG} --version     > /dev/null \
  || die "${GHC_PKG} not found."
GHC_VER=`${GHC} --numeric-version`
GHC_PKG_VER=`${GHC_PKG} --version | cut -d' ' -f 5`
[ ${GHC_VER} = ${GHC_PKG_VER} ] \
  || die "Version mismatch between ${GHC} and ${GHC_PKG} If you set the GHC variable then set GHC_PKG too"

# Cache the list of packages:
echo "Checking installed packages for ghc-${GHC_VER}..."
${GHC_PKG} list > ghc-pkg.list \
  || die "running '${GHC_PKG} list' failed"

# Will we need to install this package, or is a suitable version installed?
need_pkg () {
  PKG=$1
  VER_MATCH=$2
  if grep " ${PKG}-${VER_MATCH}" ghc-pkg.list > /dev/null 2>&1
  then
    return 1;
  else
    return 0;
  fi
  #Note: we cannot use "! grep" here as Solaris 9 /bin/sh doesn't like it.
}

info_pkg () {
  PKG=$1
  VER=$2
  VER_MATCH=$3

  if need_pkg ${PKG} ${VER_MATCH}
  then
    echo "${PKG}-${VER} will be downloaded and installed."
  else
    echo "${PKG} is already installed and the version is ok."
  fi
}

dep_pkg () {
  PKG=$1
  VER_MATCH=$2
  if need_pkg ${PKG} ${VER_MATCH}
  then
    echo
    echo "The Haskell package '${PKG}' is required but it is not installed."
    echo "If you are using a ghc package provided by your operating system"
    echo "then install the corresponding packages for 'parsec' and 'network'."
    echo "If you built ghc from source with only the core libraries then you"
    echo "should install these extra packages. You can get them from hackage."
    die "The Haskell package '${PKG}' is required but it is not installed."
  else
    echo "${PKG} is already installed and the version is ok."
  fi
}

fetch_pkg () {
  PKG=$1
  VER=$2

  URL=${HACKAGE_URL}/${PKG}/${VER}/${PKG}-${VER}.tar.gz
  if which ${CURL} > /dev/null
  then
    ${CURL} -C - -O ${URL} || die "Failed to download ${PKG}."
  elif which ${WGET} > /dev/null
  then
    ${WGET} -c ${URL} || die "Failed to download ${PKG}."
  else
    die "Failed to find a downloader. 'wget' or 'curl' is required."
  fi
  [ -f "${PKG}-${VER}.tar.gz" ] \
    || die "Downloading ${URL} did not create ${PKG}-${VER}.tar.gz"
}

unpack_pkg () {
  PKG=$1
  VER=$2

  rm -rf "${PKG}-${VER}.tar" "${PKG}-${VER}"/
  ${GUNZIP} -f "${PKG}-${VER}.tar.gz" \
    || die "Failed to gunzip ${PKG}-${VER}.tar.gz"
  ${TAR} -xf "${PKG}-${VER}.tar" \
    || die "Failed to untar ${PKG}-${VER}.tar.gz"
  [ -d "${PKG}-${VER}" ] \
    || die "Unpacking ${PKG}-${VER}.tar.gz did not create ${PKG}-${VER}/"
}

install_pkg () {
  PKG=$1

  [ -x Setup ] && ./Setup clean
  [ -f Setup ] && rm Setup

  ${GHC} --make Setup -o Setup \
    || die "Compiling the Setup script failed"
  [ -x Setup ] || die "The Setup script does not exist or cannot be run"

  ./Setup configure ${SCOPE_OF_INSTALLATION} "--prefix=${PREFIX}" \
    --with-compiler=${GHC} --with-hc-pkg=${GHC_PKG} \
    ${EXTRA_CONFIGURE_OPTS} ${VERBOSE} \
    || die "Configuring the ${PKG} package failed"

  ./Setup build ${VERBOSE} \
    || die "Building the ${PKG} package failed"

  ./Setup install ${VERBOSE} \
    || die "Installing the ${PKG} package failed"
}

install_pkg_cabal () {
  PKG=$1

  [ -x Setup ] && ./Setup clean
  [ -f Setup ] && rm Setup

  ${GHC} --make Setup -o Setup \
    || die "Compiling the Setup script failed"
  [ -x Setup ] || die "The Setup script does not exist or cannot be run"

  ./Setup configure ${SCOPE_OF_INSTALLATION} "--prefix=/opt/sfw/libexec/cabal" \
    --with-compiler=${GHC} --with-hc-pkg=${GHC_PKG} \
    ${EXTRA_CONFIGURE_OPTS} ${VERBOSE} \
    || die "Configuring the ${PKG} package failed"

  ./Setup build ${VERBOSE} \
    || die "Building the ${PKG} package failed"

  ./Setup copy --destdir=$RPM_BUILD_ROOT || die "Installing the ${PKG} package failed"
}

do_pkg () {
  PKG=$1
  VER=$2
  VER_MATCH=$3

  if need_pkg ${PKG} ${VER_MATCH}
  then
    echo
    echo "Downloading ${PKG}-${VER}..."
    fetch_pkg ${PKG} ${VER}
    unpack_pkg ${PKG} ${VER}
    cd "${PKG}-${VER}"
    install_pkg ${PKG} ${VER}
    cd ..
  fi
}

# Actually do something!

info_pkg "parsec"  ${PARSEC_VER}  ${PARSEC_VER_REGEXP}
info_pkg "network" ${NETWORK_VER} ${NETWORK_VER_REGEXP}
info_pkg "Cabal"   ${CABAL_VER}   ${CABAL_VER_REGEXP}
info_pkg "mtl"     ${MTL_VER}     ${MTL_VER_REGEXP}
info_pkg "HTTP"    ${HTTP_VER}    ${HTTP_VER_REGEXP}
info_pkg "zlib"    ${ZLIB_VER}    ${ZLIB_VER_REGEXP}

do_pkg "parsec"  ${PARSEC_VER}  ${PARSEC_VER_REGEXP}
do_pkg "network" ${NETWORK_VER} ${NETWORK_VER_REGEXP}
do_pkg "Cabal"   ${CABAL_VER}   ${CABAL_VER_REGEXP}
do_pkg "mtl"     ${MTL_VER}     ${MTL_VER_REGEXP}
do_pkg "HTTP"    ${HTTP_VER}    ${HTTP_VER_REGEXP}
do_pkg "zlib"    ${ZLIB_VER}    ${ZLIB_VER_REGEXP}

install_pkg_cabal "cabal-install"

echo
echo "==========================================="
CABAL_BIN="$PREFIX/bin"
if [ -x "$CABAL_BIN/cabal" ]
then
    echo "The 'cabal' program has been installed in $CABAL_BIN/"
    echo "You should either add $CABAL_BIN to your PATH"
    echo "or copy the cabal program to a directory that is on your PATH."
    echo
    echo "The first thing to do is to get the latest list of packages with:"
    echo "  cabal update"
    echo "This will also create a default config file (if it does not already"
    echo "exist) at $HOME/.cabal/config"
    echo
    echo "By default cabal will install programs to $HOME/.cabal/bin"
    echo "If you do not want to add this directory to your PATH then you can"
    echo "change the setting in the config file, for example you could use:"
    echo "symlink-bindir: $HOME/bin"
else
    echo "Sorry, something went wrong."
    echo "The 'cabal' executable was not successfully installed into"
    echo "$CABAL_BIN/"
fi
echo

rm ghc-pkg.list
